Power press



May 4, 1937. A, w. FRASER*- POWER PRESS Filed March 14, 1935 5 Sheets-,Sheet l R O T N E V m ALEXANDER W. FRASER May 4 1937- A. w. FRASER v2,079,553

POWER PRESS Filed March 14, 1955 5 Sheets-Sheet 2 I lNyENToR ,l ALEXANDER FRASER May 4, 1937. A. W FRASER 2,079,553

POWER PRESS Filed March 14, 1955 3 Sheets-Sheet 5 f ,o T515- INVENToR ALEXANDER W. FRASER ATT'ORNEY Patented May 4; 1937 UNITED STATES PGWER PRESS Alexander W. Fraser, Hamilton, Ontario, Canada, assignor to National Steel Car Corporation,

Limited, Hamilton, tion of-Canada' Ontario, Canada, a corpora- Application Marsh r4, 1935, serial No. 10,975

21 Claims.

'Ihe invention relates in general to power presses of general application and particularly relates to a power press for forming corrugations in steel car ends, car sides, car doors and similar 5 heavy metal structural parts of railroad cars and other building constructions, together with improved forms of dies for the same, and the invention is specifically designed to fabricate the car ends disclosed in my Patent No. 1,996,004

granted on March 26, 19,35, application Serial Y No. 700,098, iiled November 28, 1933.

The car ends in the said patent are characterized by having a reinforcing corrugated area spaced inwardly from the outlining edges and in which the corrugated area is formed of two sets of corrugations, with the corrugations of each set extending parallel to each other; the corrugations of one set intersecting the corrugations of the other set to form a checker-board design and wherein the corrugations are each of a U- shaped at web and inclined side wall type, with relatively narrow corrugations forming one set identified as vertical posts extending with uniform cross sectional conguration from end to 25 end, hurdling or overlapping the relatively wide horizontal corrugations of the other set, sometime hereinafter identied as horizontal girders.

The primary object of the invention is to provide a simplified means for forming corrugations 30 such as form the corrugated area of. the said patented car end.

Corrugated car ends of the type under discussion are usually formed in one or more sections With dimensions when formed of one piece,

35 substantially eight or nine feet wide, four to five feet high, and with a. thickness of three to ve sixteenths of an inch, and are usually made by die pressing high grade rolled sheet steel. It is the usual practice to form one of the sections constituting the car end in a single die-stamping operation and this procedure necessitates certain refinements of practice, such for instance, as the maintaining of this large area plate at a relatively high temperature and the employment of large sized presses of the order of two thousand five hundred ton presses.

The present method features the forming of the corrugated area of such plates by die-press- 50 ing relatively' small portions of theplate in each of a series of succeeding stamping operations, and the forming of corrugations in plates of large area on a relatively small size press. In one method of practicing the invention, the corrugations can be formed on a press of relatively (ci. 15s-.16)

low capacity, such as a one thousand ton type of press, thus permitting of the fabrication of heavy type die-pressing of car ends on presses commonly found in the ordinary car and railroad repair shops.

The invention also features the utilization of the previously formed relatively narrow intersecting or transverse corrugations or parts thereof to prevent accidental shifting of the plate in directions at right angles to each other in the plane of the plate, and also features an intensity of clutching engagement in the part of the plate not yet acted upon to permit a restrained creeping of the metal from the part so held into the part being acted upon by the dies, and thus tend to minimize any action of the dies in thinning out the material in the part forming the corrugations, While holding the material not yet worked, or not intended to be worked upon, from any incidental warping.

Referring particularly to the apparatus aspect of the disclosure another object of the invention isto provide a form of die press, or more particularly, a simple form of coasting dies of such a press for practicing the above outlined method economically on a power press, even on a power pressof relatively light power.

Still another object of the invention is to provide in a power press of the type herein featured, an organization of the'separate parts which will `permit the formation of the desired corrugated area with that nicety of control of the material being worked upon to permit the formation of the required corrugations without unduly thinning out the material forming each corrugaticn and the providing of that degree of clutching intensity which will permit a. relatively cold ow of material to the part forming the corrugation and at the same time minimize, if not eliminate objectionable buckling in the parts immediately adjacent the corrugation being formed.

This phase of the invention is provided by utilizing a work-holding clutch which will hold the at portions of the plate adjacent and outlining the portion at the time being formed into corrugations, with an intensity of clutching action suiiiciently great to prevent buckling but not so high as to prevent the desired edgewise creeping of the material from the uncorrugated into the portion in which the corrugation is being formed for the time being. In this connection it is suggested that the work holding clutch have a slightly greater clearance at the intake end of the material than at the discharge end adjacent the corrugation forming side thereby to facilitate feeding of the plate into the portion being corrugated. i

Various other objects and advantages of the invention will be in part obvious from a consideration of the method features of the disclosure and from an inspection of the accompanying drawings and in part will be more fully set forth in the following particular description of one method of practicing the invention, and the invention also consists in certain new and novel modifications of the preferred method as well as to the products produced following such method or methods.

In the accompanying drawings:

Figs. 1 to 4 and the upper portion of Fig. 5 are explanatory views illustrated as if in end elevation of a die press showing successive stepsin corrugating sheet metal in practicing the method herein featured, but more properly showing somewhat diagrammatically an end'view of the structure shown in Figs. 6, '1 and 8 with the end pieces of the cushioning frame omitted, and illustrating a preferred embodiment of the apparatus features of the disclosure;

Fig. 5 is a view partly in section and partly in an end elevation viewv of the structure shown in Figs. 6, 7 and 8 and illustrating a power means for operating the upper die and a cushioning means for the lower die;

Fig. 6 is an enlarged plan view of opposite ends of the lower die shown in the preceding gures and with the midportion broken away;

Fig. 7 is a view in elevation of the upper die looking at the same from the right side of the showing inrFigs. 1 to 5:

Fig. 8 is a similar view of the companion parts of the lower die;

Fig. 9 is a view in elevation of the lower right hand corner of a car end constructed by following the method herein featured and corresponding to Fig. 1 in the above identified copending application. It can be assumed also that either the lower or upper half of this gure also represents a plan 'view of either one of the dies shown in end elevation in the preceding figures, it being understood, of course, thatvboth the upper and lower dies are each of twice the length of the showing in Fig. l; and

Fig. l0 is a perspective view of a portion of the car end show-n in Fig. 9, showing one of the vertical corrugations intersecting two of the horizontal corrugations, but likewise it can be assumed that the showing in Fig. 10`is a portion of one of the dies which forms the correspondingly shaped portion of the car end.

Referring to the finished structure, there is eventually formed a substantially flat sheet metal plate or panel lil having inturned side flanges il and an outlining flat uncorrugated edge portion i2. Within the outlining flat edge area i2 the plate is providedwith two sets of corrugations to form a central reinforced area to the panel as a whole; one set of corrugations i3 being relatively numerous extends horizontally in parallel relation and the copending disclosure features the forming of these corrugations equidistantly spaced apart to form integral girders in the finished plate. 'Ihe other set of corrugations Il being less numerous and in the instant case constituting four, are relatively narrow and extend vertically, and like the horizontal corrugations in the copending disclosure feature the forming of these vertical corrugations substantially equidistantly spaced apart horizontally. These corrugations intersect each other at right angles to form an elongated block-like or checkerboarddesign over the entire reinforced area. The trough or channel i5 cf the girder forming corrugation I3 is continuous across the entire reinforcedarea and is straight from end to end. The trough or channel i6 of the post forming corrugation i6 is likewise continuous from end to end across the reinforced area but of course is not straight being of undulatory form. The post forming corrugations I4 are continuous and project outwardly not only from the at uncorrugated portion of the plate but extend up the sides of, pass over and project beyond the corrugations I3 as shown at I8, Fig. 10. The posts It then extend over the girder forming corrugations I3 and along the trough or uncorrugated space 20 formed between the adjacent pairs of the girder forming corrugations I3.

Referring to the showings in Figs. 1 to 8 it will be understood that there is illustrated a conventional form of die pressing machine including a stationary bed 2i and a movable power actuated plunger 22 mounted for vertically reciprocatory movement. A relatively stationary two part male die t is carried by the bed 2i om the upper side thereof and the plunger 22 is provided on its underside with a one-piece coacting female die 2t.

The die 23 is formed primarily of two relatively movable parts: a middle, long rectangular bar or strip 25 rigidly secured to the bed 2i, and. an encircling or rather middle bar-enclosing, rectangular, hollow fe. The frame includes two long outside strip bars or plates 26 and 2li, extending parallel to and in edgewise vertical sliding engagement with opposite long sides of the middle strip 25 and two connecting end members or blocks i2 and @33. The strips 2d and 2 are secured together at their ends with the end members d2 and i3 forming spacing members therebetween by means of readily replaceable through bolts M as shown in Fig. 6. It is also suggested that the wear surfaces of the parts, particularly the at surfaces of the dies, be formed of replaceable small size plates, such as are shown at t5 in Fig. 6 and that each of these plates be secured to the dies 22-24 by means of machine screws d6. The frame constitutes a cushioned pad controlled in its vertical -movement in the bed by means of supporting legs 28 passing through the bed 2i, through a bolster di carried by a press bed B8 and resting on top of a pressure cushion @il guided for vertical movement in the press bed. The frame is normally,maintained in position elevated above the bed 2i, by means of cushioning springs 5@ bearing upwardly against the pressure cushion 49 or, in some forms of such presses, by pneumatic cushions, or plungers, such as are commonly found in presses of this character. In the instant case the pads have a resistance to being depressed equal to about one fth of the force inherent in the plunger 22 acting to depress the pad forming frame. The strip 26 has a smooth top face 29 and constitutes in the right hand side of the showing one of the elements of a at-face Work-holding jaw or clamp for securing the work plate as hereinafter outlined. The top surface of strip 26 is continuous and on the same level with the top surface of the end blocks 62 and f3 and with the fiat faces of the strips 25 and 21.

` envases and all of the glrder forming corrugations I3 and each heli length of said rib having the shape `in plane shown at any of the strips marked I3.

The top face of each of these strips 25 and 21 is provided on .opposite sides of the base of its rib with a fiat top face; the faces on opposite sides of rib 30 marked 3| and 32 and the similar faces on opposite sides of rib 3| marked 33 and 34. The two top faces 3| and 34 when in the position shown in Figs. 3 and 5 maintain the trough or uncorrugated spaces 20 in the finished structure.

The top, die-forming surface of each of the strips 25 and 21 is also provided with a plurality, in the instant case with four, transversely extending beads 35 and 38, one for forming each of the upstanding relatively narrow corrugations I4. It is understood, of course, that each bead extends when the pad 21 ls in its lowermost position continuously across and between the two ribs 32 and 3|.

The die 26 is formed as the negative or complement oi the two part 'die 23, except that the portion 31 immediately above and forming the coacting element of the clutch jaw 26 is formed flat and preferably polished as is the top face of the oating clutch element 26 but has a greater clearance at its outer edge. as indicated at 38',

than at its inner edge 39 when the die elements are in their proper corrugation forming relation. The left two-thirds oi the underside of the die 24 is provided with two identical channels 40 and 4| for receiving respectively the ribs 3|] and 3| and withtransversely extending smaller grooves 42, one for each of the beads 35--36. When viewed in plane, a part of the underside ofdie 24 corresponds to the showing in Fig. 10 in its inclusion of two grooves i5 and one of the transverse grooves I5.

It will be understood thatithe press is provided with conventional parts such, for instance, as means for adjusting the cushioning tension on the oating pads, feed tables for feeding the stock to the press and for `withdrawing the finished product from the press and with guides and templets for locating the stock in its initial position in the press and means for heating the plate for the time being acted upon.

In operation and reierring'first to the showing of the parts in Fig. 1 with the plunger and pads in their normal elevated position, the plate p to be corrugated is advanced into the machine in the direction indicated by the arrows in Figs.

1 and 10 until the advanced edge `e meets a stop i (not shown) but located to bring the channel I6 at the upper edge of the end plate as shown in Fig. 9. Other stops `are used to insure the requisite width of edge portion I2 and flange Il to this particular piece of work. At this time the plate assumes roughly the position indicated in Fig. 1.

Power is then turned on to lower the plunger 22 and during the lowering movement at this initial operation two actions take place. First, the left portion of the coacting dies, that is the pad 21 and the coacting part immediaely above v rugatlon I 31 *is more or less completely formed.

At this time there is formed not only the corrugation |31 but the intersecting portions of each of the corrugations 4I4 embraced within the bracket marked |31, Fig. 9. It will thus be seen that the advanced edge of the plate is held between the left hand portion of the dies and is held from movement in the direction of advance of the` plate (shown by the arrow) by the rib 3|, and is held from lateral movement in the transverse direction by the several sections |41 of the transversely extending corrugations engaging over the beads 3B.' While this advanced corrugated portion of the plate is thus being held with any desired degree of clutching intensity controlled by the springs acting on pad 21, the machine is so designed that the clutch 26-31 with their connecting end pieces 42 and `43 is holding the uncorrugated portion ofthe plate between its jaw elements with sufficient intensity to prevent this part of the Yplate from buckling, but with suflicient slipping to permit the held portion of the I Tracing the continued lowering movement of the plunger, the parts nally arrive in the position shown in Fig. 3 at which time the frame 26-21-42-43 is being pressed firmly into engagement with the bed 2| and both of the corrugation forming parts of the dies have completed their final pressing action so that at the end of the step indicated in Fig. 3, the first two corrugations |31, |32, have been completely formed, and the adjacent flat portions surrounding the same have been kept flat.

The upper die is then elevated to its normal raised position and the corrugated edge of the plate is then raised out of engagement with the lower die elements. The plate is then advanced one step inthe direction of the arrows and into its next succeeding position in the die assembly, the second corrugations i32 being located on the rib 3| of the ilioating pad 21, and, of course, with the transverse corrugation portion |32 fitted over the beads 36 of this floating pad and the parts are then in position to form the third corrugation |33. The plunger is lowered with the second or succeeding stroke of the machine, first into the position shown in Fig. 4 so as to clamp the second corrugation in position between the die elements and in this way to hold the second corrugation ilrmly in place during the operation of forming the third corrugation. The third corrugation is formed beginning with the position of the dies as shown in Fig. 4 and ending with the position of the dies as shown in Fig. 5, at which time the third corrugation |33 and its associated transverse portions |43 are formed, while the surrounding flat portion is held in such flat position.

It will be understood that this operation is repeated, each previously formed corrugation being utilized as a holding and spacing means to locate the next succeeding parallel wide corrugation and associated part of the continuous secting jcorrugations. h By practicing the method herein disclosed it is possible to form a one-piece corrugated car end or similarly large construction unit without necessity of using the powerful presses heretofore found necessary in pressing car ends into their requisite corrugated forms.

As cach corrugation after the first one is formed by the same die part and the coacting part immediately above 25, 'it follows that all of the wide corrugations I3 are of identical contour and that at the endof the procedure each transverse oorrugation I4 is of identical conformation throughout its length, thus providing a car end of any desired number of corrugations I3 formed from a die assembly composed only of two corrugation forming parts. Even though the high, or most advanced, portions I8 of the corrugations I 4 are pressed out of the plane of the flat sheet considerably in advance of the depth of the channels I5, the refinement practiced in this method of permitting the creeping of the plate intothe portion being formed into corrugations results in forming each corrugation separately without appreciably thinning out the metal as it is curved into the U-form in cross section characterizing the corrugations in the finished plate. Finishing the clutching facesof the jaw elements with a machine smooth finish minimizes frictional resistance to the advance of the metal into the trough forms while the portion of the plate next to be corrugated,`as well as the outlining edge portions, are held in their initial fiat condition and are thus freed from strain and lines -of weakness which might otherwise occur when the flat portions are subsequently subject to the action of the corrugation forming dies. It will be understood, of course, that the clearance illustrated in Figs.l 1 to 5 between Ithe jaw elements has been purposely exaggerated in order l to show it, but in actual practice the increase in clearance is slight and the action might be more properly designed as having less clutching intensity at the 'incoming edge 38 of the clutch. than at the discharge edge 39 adjacent the fixed die element. e

While there has been shown, described and pointed out in the annexed claims, certain novel f features of the invention, it will be understood that various omissions, substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention.

I claim:

1. A press for forming corrugations lnsheet metal including a supporting bed, means forming a relatively fixed lower die comprising three parallel strips in edge to edge side abutting relation, the middle strip being immovably fixed to the bed and the two outside strips constituting floating pads connected to move in unison and .normally supported resiliently in spaced' relation above the bed and adapted to be lowered against the resistance of their resilient supports into stopped engagement with the bed, the

" middle strip and one of the outside pads each having its upper die surface fashioned to provide a die for forming a single' corrugation and said fixed die and said oating die coacting when the die forming pad is in its lowered position to form in outline two identical forms of corrugations with an intervening trough therebetween,

apresta the toprof the other floating pad being fiat and `polished and constituting a jaw of a work holding clamp, and a movable upper die having a part of its die forming under surface fashioned to provide the negative of the contour of the said. two corrugations and intervening trough and another part of itsundersurface'flat and constltuting the coacting :law of the holding clamp.

29A press for forming corrugations ln sheet metal including a supporting bed, means forming a relatively fixed lower die comprising three parallel strips in edge to 'edge sideabutting relation, the middle strip being immovably fixed to the bed and the two outside strips constituting i. floating pads being normally supported resiliently constituting a jaw of a work holding clamp, and

a movable upper die having a part of its die forming undersurface fashioned to provide the negative of the contour of the said two corrugations and intervening trough and another part of.

its undersurface flat and constituting the coacting jaw of the holding clamp, said pads having .a resistanceto being ,depressed'into engagement with the bed equal to about one-fifth of the force inherent in the movable die acting to so depress the pads. i

3. A press for forming corrugations in sheet metal including a supporting bed, means forming a relatively fixed lower die comprising two parallel strips in side abutting relation, one of the strips being fixed to the bed and the other strip being resiliently supported, and forming a floating pad, the top surface of the fixed strip forming an element of a corrugating die and the top surface of the pad normally spaced above the die a distance equal to the depth of the corrugation formed by the press, said top surface of tle pad being iiat and forming a jaw of a clamp for holding the sheet while being pressed, and means forming a movable upper die having part of its undersurface fashioned to form the negative of the die forming face of the fixed die and coacting therewith to form a corrugation in a sheet of metal held by the clamp in position between the dies and said movable die having part of its undersurface flat and formingthe coacting element of the clamp.

4. A press for forming corrugations in sheet metal including a supporting bed, means forming a relatively fixed lower die comprising two parallelfstrips in side abutting relation, one of the strips being fixed to the bed and the other strip being resiliently supported, and forming a oating pad, the top surface of the fixed strip forming an element of a corrugating die and the top surface of the pad normally spaced above the die a distance equal to the depth of the corrugation formed by the press, said top surface of the pad being fiat and forming a jaw of a clamp for holding the sheet while being pressed, and means forming a movable upper die having part of its undersurface fashioned to form the negative of the die forming face of the fixed die and coacting therewith to form a corrugation in a. sheet aorasea ci metal held by the clamp in position between at the outer edge of the oating pad.

5. A die assembly including a male die having its work face fashioned to provide a longitudinally extending rib with at faces extending outwardly from the base of the rib and said work faces provided with a transversely extending rib of uniform cross sectional form projecting continuously above the fiat faces and the top and sides of the first-named rib and a coacting female die having a longitudinally extending groove forming the negative of the rst-named rib and having a transversely extending groove forming the negative of the transverse rib.

6. A die assembly including a male die having its work face fashioned to provide a longitudinally extending rib with flat faces extending outwardly from the base of the rib and said work faces provided with a transversely extending rib of uniform cross sectional form projecting continuously above the iiat faces and the top and sides of the first-named rib and coacting female die having a longitudinally extending groove forming the negative of the ilrst-named rib and having a transversely extending groove forming the negative of the transverse rib, and a second resiliently supported pad located on the side of the iixed die element opposite the first-named pad and coacting with a portion of the movable die opposite the same to resiliently clamp the portion of the plate in rear of the portion being acted upon by the xed die element whereby the plate is clamped simultaneously on both sides of the portion being die formed into a corrugation.

7. A press for forming a corrugation in sheet metal parallel to and spaced from a previously formed similar corrugation, means forming a relatively fixed die comprising two elements, one xed in position and the other resiliently supported, the top die forming surfaces of both elements being of identical contour and each including a rib-like member having substantially flat surfaces on opposite lateral sides thereof and a coacting movable member having its underside provided with two spaced apart parallel grooves corresponding to and located opposite to the riblike members.

8. A press for forming a corrugation in sheet metal parallel to and spaced from a previously formed similar corrugation, means forming a relatively fixed die comprising two elements, one xed in position and the other resiliently supported, the top die forming surfaces of both elements being of identical contour and each including a rib-like member having substantially ilat surfaces on opposite lateral sides thereof and a coacting movable member having its underside provided with two spacediapart parallel grooves l corresponding to and located opposite to the riblike members, the die surfaces also provided with laterally extending coacting transverse die forming ribs and grooves formed with transverse ribs projecting from both of the elements provided with the rib-like member and the transverse grooves being formed on the underside of the movable die and each groove being continuous across both of the first-named parallel grooves and across the intervening surface.

9. In a press for forming spaced apart parallel corrugations in a plate. the combination of a support, means forming a relatively xed lower die carried by the support and including two die forming elements extending parallel to each other, one fixed to the support and the other resiliently supported and forming a oating pad adapted to bemoved into a stopped position engaging the support and disposed with its top surfacenormally positioned above the top surface of the xed element, each of said top surfaces provided with a longitudinally extending rib-like member for forming or securing in place one of the corrugations in the ed plate and said top surfaces each provided on opposite sides of its respective rib with a flat surface, the fiat surface adapted to be moved into alignment when the pad is lowered into engagement with the support, and a coacting one-piece movable upper die having its undersurface provided with two spaced apart parallel grooves corresponding in contour to the rib-like member and the portion of the movable die opposite the pad coacting therewith to hold a previously formed corrugation therebetween wliile the xed element and the portion of the movable die opposite the same is acting on the plate to form the next adjacent corrugation spaced from the held corrugation a distance determined by the width of the ilat portions between the two rib-like die members.

10. A die for use in forming corrugated plates provided in its die face with two parallel and transversely spaced apart relatively wide grooves with a substantially flat face therebetween and i said die face also provided with a plurality of laterally extending parallel, spaced apart relatively narrow grooves, each of Asaid narrow grooves extending continuously and without change in cross sectional configuration across both of the portions of the die face provided with two wide grooves and across the ilat space between the two wide grooves, and a coacting die including two relatively wide rib-like members. one for each of the wide grooves and located opposite the same and a plurality of transverse relatively narrow beads, one for each narrow groove, projecting beyond the rib-like members.

11. In a. machine for forming corrugations, two coacting dies, power means acting on one of the dies to move the same into cooperative relation to the other, one of said dies including a single element and the other die comprising two elements, one fixed in place and the other forming a frame encircling the single element and being resiliently mounted and capable of being moved against the resistance of its resilient mounting when engaged by the other die, said dies having their work engaging faces each fashioned to dene a corrugation and said frame having its work engaging face fiat and constituting an element of a clutch, the die comprising the single element having its work engaging face fashioned in one part to form the complement of and opposing the corrugation deflning faces, o ftl 1 e said two elements and another part being flatfand constituting the coacting element of the clutch.

v12. In a die press for forming corrugated car ends having a corrugated area outlined at opposite edges with at uncorrugated marginal portions, said press including two relatively movable coacting dies, one of said dies including a central portion rigid with its support, and a frame encircling the central portion and resiliently mounted for movement to and from said support, said central portion and the coacting part of its companion die provided with means for forming 13. In a die press for forming corrugated car ends having a corrugated arca outlined at opposite edges with ilat uncorrugated marginal portions, said press including two relatively movable coacting dies. one oi.' said dies including a central portion rigid with its support. and a frame encircling the central portion and resiliently mounted for movement to and from said support, said central portion and the coacting part of its companion die provided with me for forming a corrugation in a metal plate held between the dies, and the part of the le on one side of the central portion and the coact part of its companion die alsoprovided with means for forming a corrugation in the metal plato, said means being of identical ;v tion, whereby the corrugation formed by one oi said means will ilt the other means.

14. In a die press, the combination of a support, a rectangular hollow frame resiliently supported from said support, a bar iltted in said frame and rigidly secured to the support. the bar and a side of the frame on one side oi the bar each provided with a corrugation-forming die element, said elements extending parallel to each other, being transversely spaced apart. and of identical contour.

15. In a die press, the combination of a support, a rectangular hollow frame resiliently supported from said support. a bar iitted in said frame and rigidly secured to the support, the bar and a side of the frame on one side of the bar each provided with a corrugation-forming die element, said elements extending parallel to each other, being transversely spaced apart, and of identical contour, and each element including a part extending transversely of the length of said parallel elements and one of said parts adapted to form a continuation of the other.

16. A die press including a die comprising a bed, a long, middle strip secured to the bed, a pair of side strips disposed on opposite sides of said middle strip. end pieces connecting opposite ends of the side strips and coating therewith to form a rectangular frame surrounding the middle strip, means for supporting the frame resiliently from the bed. said middle strip and one of said side strips provided with an element of a corrugation-forming member, said elements extending parallel to each other and transversely spaced apart, the work face of said middle strip and said side strip on opposite sides of said element being ilat and the work face of the other side strip being ilat, and a coacting die having work-engaging faces forming the complement of the work face of the rst-named die and acting on the frame to move the same into a stopped engagement with the bed and against the resistance of its resilient support.

17. In a power press, the combination oi' coacting dies, including corrugation-forming means.

and work-clamping means entirely surrounding said forming means for securing the part of the work adjacent the part being acted upon by the corrugation-forming means and' said clamping means including a corrugatlon constituting a duplication oi said forming means.

18. In a power press, the combination oi coacting dies with a part of one of said dies forming a cushioned padsurrounding the balance of said die, and said balance of said die as well as the part surrounded thereby being each provided on its work-engaging face with an element of a corrugation-torming means surrounded by a hat uncorrugated face.

19. A press for successively forming identical parallel corrugations in a sheet, comprising two coacting dies, one of said dies being of one piece and the other being oi three relatively movable pieces, considered transversely of the lengths of the corrugations, two of said three pieces and the coacting portion of the other die having their die forming surfaces the complement of each other, each of said two pieces and its coacting part of the other die providing means for forming a complete corrugation and the third piece coacting with its .companion portion on the other die to provide a dat-faced clamp and means for cushioning said ilatiaced clamp.

20. A press for successively forming identical parallel corrugations in a sheet comprising two coacting dies, one of said dies including two parts, said two parts having their die forming surfaces the complement of the coacting portion oi' the other die, each of said two parts and its coacting part of the other die being of identical contour and providing means for forming a complete corrugation whereby a corrugation formed by one of said parts and its associated portion'will fit the other part and its associated portion and said coacting dies including coacting clamping members for clamping a flat portion of the sheet while another portion is acted upon by the corrugating dies. said clamping members provided with non-parallel clamping faces.

21. A press for successively forming identical dat corrugations in sheet metal as the metal is fed therethrough, said press comprising two coacting dies, having a portion oi.' the die surface of one constituting the complement of its coacting portion on the other die, said portion of one of the die surfaces including two identically shaped wide fiat grooves extending in parallel relation and spaced apart to form a wide fiat rib'th'erebetween and the companion portion of the other die similarly provided with two identically shaped wide 4ilat ribs opposing and coacting with the two grooves and forming a groove therebetween opposing and coacting with the rib and one ofsaid dies being divided along a plane intersecting the ilrst named rib and its coacting last `named 60 groove to form two relatively movable parts to said die.

ALEXANDER W. FRASER. 

